In the discussion about demographic change, the regional dimension so far has played a subordinate role. Based on municipal data for the period between 1998 and 2008, this paper examines to what extent recent demographic change has affected the population of cities and neighbourhoods, focusing on the largest urban agglomeration in Germany, the Rhine-Ruhr conurbation in North Rhine-Westphalia. The local outcomes of demographic change are modified considerably by regional migration and interrelate closely with regional prosperity. The survey provides a precise outline of the interrelation between basic demographic characteristics and shifts in the composition of neighbourhood populations over the study period. The analysis shows that in the most thriving cities, there is a particularly strong tendency of young adults to separate from other demographic groups. In neighbourhoods where there is no such influx of younger people, particularly in low-density residential areas on the urban fringe, rapid demographic ageing aff ects neighbourhood populations and local economies.